The present disclosure relates to a linear vibrator.
Recently, as the release of personal digital assistants (PDA) having large liquid crystal display (LCD) screens for user convenience has rapidly increased, a touch screen scheme has been increasingly adopted for use therewith, and a vibration motor for generating vibrations at the time of a touch has come into common use.
Such a vibration motor, a component converting electrical energy into mechanical vibrations using the principle of generating electromagnetic force, is mounted in the PDA to thereby be used for silently notifying a user of call reception by transferring vibrations thereto.
According to the related art, a scheme of obtaining mechanical vibrations by generating rotary force through rotation of a rotor part having an unbalanced mass has been used. In this scheme, the rotary force is converted into mechanical vibrations by a rectifying action through a contact point between a brush and a commutator.
However, in a brush type structure using a commutator, since the brush passes through a clearance between segments of the commutator at the time of rotation of the motor, mechanical friction and electrical sparks may be caused and foreign materials may be generated, such that a lifespan of the motor may be reduced.
In addition, since time may be taken to arrive at a target amount of vibrations due to rotational inertia at the time of application of voltage to the motor, there may be a problem in implementing an appropriate amount of vibrations in a touch screen.
A linear vibrator has been mainly come into use in order to overcome disadvantages in terms of lifespan and response characteristics of the motor and to allow a vibration function to be implemented in the touch screen.
The linear vibrator does not use the principle of rotation of the motor, but uses a principle in which electromagnetic force, obtained through a spring installed in the vibrator and a mass body suspended from a spring, is periodically generated according to a resonance frequency to cause resonance, thereby generating vibrations.
In accordance with market trends for miniaturization and slimness in portable electronic devices, such a linear vibrator should be able to be slimed and be efficiently produced, and performance and characteristics of the linear vibrator should not be affected, even under the influence of several factors.
Particularly, in the case of a linear vibrator disposed within an internal space of a housing, parts of the linear vibrator are generally classified as a vibrating part and a fixed part, wherein the fixed part is fixed to the housing and the vibrating part is vibrated through electromagnetic interaction with the fixed part. Here, the vibrating part is fixed to the housing via an elastic member to implement vibration function. In this case, the elastic member is coupled to the housing using a typical welding scheme, wherein due to stress concentrated on a location at which the elastic member is welded, there is a risk of damage.
Patent Document 1, the following related art document alleviates the concentration of stress by including a pierced part in an elastic member. However, since it is relatively difficult to manufacture an elastic member having the above-mentioned structure, the unit production cost may be increased.